de-fogging lens

A problem I've never had before (until now) is lenses fogging up. I would imagine those of you in the top half of the planet may encounter this more often. Any easy solutions? I see Nikon make a de-fog cloth, any good?

Neale, Fog on the external elements is natural when you move a cold equipment into a warm humid atmosphere. Both the temperature and the humidity play critical roles, so this can happen almost any time depending on the temperature and humidity differences. One way to keep the fog off the equipment is to put it inside some sealed container (plastic bag, camera bag, etc.) and then enter the warm humid area. You need to leave the equipment in the bag until it warms up, which can be slow inside a camera bag. Wiping the fog away only works if the equipment is warmed up. It it's still cold, more fog will form. I often see this in the summer when I take my camera from my basement (65F or 18C) outside to where its hot and humid (90F or 30C and high humidity).

If you've got fog forming inside the lens, then you probably need to get the lens repaired since a seal has broken.

I use Nikon's de-fog wipes and they are great!!

When I take my camera out of my backpack into the cold, the lens will fog up. I use my hurricane blower to puff cold air onto the front lens element which removes the fog and cools the lens down so no new fog can form. While not an instant fix, it usually only takes a minute to have a clear lens.

External fog is best controlled by letting the lenses warm or cool to ambient inside your camera bag before pulling them out into the moist air.

If it's internal, that's another issue. I've seen the inner surface of the objective lens on my 500 f/4 fog once early in the morning. Talk about something to make you wince! I mounted mine on the tripod and aimed it right into the sun. By the time I got the rest of my camera gear situated the fog had reduced to a 2" or so circle, and a couple of minutes later it was gone. Whew! But now I'm very careful to let lenses reach ambient temp before pulling them out of a bag.

Neale
even when i have my gear the correct temperature (outside with it all night, or all day) if i get into a very foggy place, the lens will still fog up. I am open to any ideas. Does the Nikon defog cloth really work when the humidity is 99.99%? I am in the mid Atlantic reagion which is famous for its humidity javascript:%20x()

thanks for your responses, luckily it's only external fogging I'm dealing with, from cold air. Obviously from the sound of it, acclimatising is the way to go, though i may try the Nikon de-fog cloths anyway as they're only $2.69 on amazon.

I made an interesting discovery this last fall while hiking. I have a bad habit of putting my lens cap in my pants pocket while shooting. I discovered after hiking my leg is warmer than the lens. I would put the cap back on the lens and when it came off again, voila, fogged lens. I have started putting the cap in a location where it will not exceed the temperature of the camera when it is temporarily off.